package org.bouncycastle.jce.provider;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;
import java.security.interfaces.RSAPrivateKey;
import java.security.spec.RSAPrivateKeySpec;
import java.util.Enumeration;

import org.bouncycastle.asn1.DEREncodable;
import org.bouncycastle.asn1.DERNull;
import org.bouncycastle.asn1.DERObjectIdentifier;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
import org.bouncycastle.asn1.pkcs.RSAPrivateKeyStructure;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.crypto.params.RSAKeyParameters;
import org.bouncycastle.jce.interfaces.PKCS12BagAttributeCarrier;

public class JCERSAPrivateKey implements RSAPrivateKey,
        PKCS12BagAttributeCarrier {
    static final long serialVersionUID = 5110188922551353628L;

    private static BigInteger ZERO = BigInteger.valueOf(0);

    protected BigInteger modulus;
    protected BigInteger privateExponent;

    private PKCS12BagAttributeCarrierImpl attrCarrier = new PKCS12BagAttributeCarrierImpl();

    protected JCERSAPrivateKey() {
    }

    JCERSAPrivateKey(RSAKeyParameters key) {
        this.modulus = key.getModulus();
        this.privateExponent = key.getExponent();
    }

    JCERSAPrivateKey(RSAPrivateKeySpec spec) {
        this.modulus = spec.getModulus();
        this.privateExponent = spec.getPrivateExponent();
    }

    JCERSAPrivateKey(RSAPrivateKey key) {
        this.modulus = key.getModulus();
        this.privateExponent = key.getPrivateExponent();
    }

    public BigInteger getModulus() {
        return modulus;
    }

    public BigInteger getPrivateExponent() {
        return privateExponent;
    }

    public String getAlgorithm() {
        return "RSA";
    }

    public String getFormat() {
        return "PKCS#8";
    }

    public byte[] getEncoded() {
        // BEGIN android-changed
        PrivateKeyInfo info = new PrivateKeyInfo(new AlgorithmIdentifier(
                PKCSObjectIdentifiers.rsaEncryption, DERNull.INSTANCE),
                new RSAPrivateKeyStructure(getModulus(), ZERO,
                        getPrivateExponent(), ZERO, ZERO, ZERO, ZERO, ZERO)
                        .getDERObject());
        // END android-changed

        return info.getDEREncoded();
    }

    public boolean equals(Object o) {
        if (!(o instanceof RSAPrivateKey)) {
            return false;
        }

        if (o == this) {
            return true;
        }

        RSAPrivateKey key = (RSAPrivateKey) o;

        return getModulus().equals(key.getModulus())
                && getPrivateExponent().equals(key.getPrivateExponent());
    }

    public int hashCode() {
        return getModulus().hashCode() ^ getPrivateExponent().hashCode();
    }

    public void setBagAttribute(DERObjectIdentifier oid, DEREncodable attribute) {
        attrCarrier.setBagAttribute(oid, attribute);
    }

    public DEREncodable getBagAttribute(DERObjectIdentifier oid) {
        return attrCarrier.getBagAttribute(oid);
    }

    @SuppressWarnings("rawtypes")
    public Enumeration getBagAttributeKeys() {
        return attrCarrier.getBagAttributeKeys();
    }

    private void readObject(ObjectInputStream in) throws IOException,
            ClassNotFoundException {
        this.modulus = (BigInteger) in.readObject();
        this.attrCarrier = new PKCS12BagAttributeCarrierImpl();

        attrCarrier.readObject(in);

        this.privateExponent = (BigInteger) in.readObject();
    }

    private void writeObject(ObjectOutputStream out) throws IOException {
        out.writeObject(modulus);

        attrCarrier.writeObject(out);

        out.writeObject(privateExponent);
    }
}
